1. Field of the Invention
The present invention relates to tow vehicles of the type used for maneuvering aircraft into and out of hangers or otherwise on the ground and for servicing such aircraft.
2. Description of the Prior Art
Aircraft, such as airplanes, have a power plant which cannot be used efficiently to move the aircraft a relatively short distance. For this reason, it is advantageous to have a riding, self-propelled utility vehicle which can be used to tow the aircraft to any desired position. The self-propelled unit would be attached to the aircraft at a convenient location, such as the aircraft nose wheel, and an operator controls the tow vehicle to move the aircraft to a desired ground location for subsequent takeoff. In addition to the obvious advantages obtained from a utility tow vehicle, a need also exists for an associated aircraft engine preheater on the utility vehicle. Cold weather or climate conditions have long been a problem in the aviation field when starting the aircraft engine due to the high viscosity of lubricants and difficulty of turning the engine over. Large international and commercial airports where large aircraft are serviced typically provide mobile self-contained heaters for providing heat to aircraft. However, it is often times a problem to start smaller aircraft where such large heaters are not available or where expense makes their use prohibitive. Such a need has particularly existed in smaller airports, flying clubs, and other areas where small aircraft may be hangered. Here, the cost of a self-contained preheater can be prohibitive.
A number of tow vehicles are known in the prior art for maneuvering aircraft from one position to another. One such prior art reference is U.S. Pat. No. 3,038,550 to Lehmann et al., issued Jun. 12, 1962. The Lehmann patent shows a hand-operated, gasoline powered tow vehicle which is adapted to engage the axle of the aircraft nose wheel to connect the vehicle thereto for moving the craft over the ground. The Lehmann vehicle is used to move jet fighter planes from hangers and parking areas to the flight line. In order to eliminate blind spots in the operator's vision, a pair of handle bar grips are provided for use by operators standing on either side of the transport vehicle. A separate power pack is provided to supply electrical energy to the aircraft for starting its engine. There is no provision for preheating aircraft engines. The steering mechanism is relatively crude and, in fact, the vehicle is not intended to be ridden by the operator.
U.S. Pat. No. 4,318,448, issued Mar. 9, 1982, to Cline, shows another small towing appliance which is used by an operator to tow vehicles to the ready line. It is a relatively light, battery powered unit which is not intended to be ridden and is operated in the nature of a hand cart.
U.S. Pat. No. 4,289,095, issued Sep. 15, 1981, to Scherr, shows a preheater for aircraft engines which utilizes as a source of thermal energy the hot water from an automobile engine. The preheater is not associated with a towing vehicle ridden by an operator.
The present invention has as one object to provide an improved towing vehicle which permits rapid and safe maneuvering of the vehicle.
Another object of the invention is to provide a relatively economical aircraft moving unit which can be utilized in the light aircraft industry by ground service or fixed base operators.
Another object of the invention is to provide an aircraft ground towing vehicle which is relatively light in weight and of small frame for ease of maneuverability in confined areas.
Another object of the invention is to provide a ground towing vehicle for aircraft which is adapted to engage a tow bar provided for use with a given aircraft, the vehicle being ridden by an operator during use.
Another object of the invention is to provide a tow vehicle which incorporates all of the commonly needed service features for servicing light aircraft and helicopters, with all of the necessary tools being provided in a compact unit.
Additional objects, features and advantages will be apparent in the written description which follows.